Moorlag Carolyn, Wolf Michael O, Bohne Cornelia, Patrick Brian O
Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada.
J Am Chem Soc. 2005 May 4;127(17):6382-93. doi: 10.1021/ja043573a.
We report the preparation of complexes in which ruthenium(II) bis(bipyridyl) groups are coordinated to oligothiophenes via a diphenylphosphine linker and a thienyl sulfur (P,S bonding) to give Ru(bpy)(2)PT(3)-P,S(2) (bpy = 2,2'-bipyridyl, PT(3) = 3'-(diphenylphosphino)-2,2':5',2' '-terthiophene), Ru(bpy)(2)PMeT(3)-P,S(2) (PMeT(3) = 3'-(diphenylphosphino)-5-methyl-2,2':5',2' '-terthiophene), Ru(bpy)(2)PMe(2)T(3)-P,S(2) (PMe(2)T(3) = 5,5' '-dimethyl-3'-(diphenylphosphino)-2,2':5',2' '-terthiophene), and Ru(bpy)(2)PDo(2)T(5)-P,S(2) (PDo(2)T(5) = 3,3' '' '-didodecyl-3' '-diphenylphosphino-2,2':5',2' ':5' ',2' '':5' '',2' '' '-pentathiophene). These complexes react with base, resulting in the complexes [Ru(bpy)(2)PT(3)-P,C]PF(6), [Ru(bpy)(2)PMeT(3)-P,C]PF(6), [Ru(bpy)(2)PMe(2)T(3)-P,C]PF(6), and [Ru(bpy)(2)PDo(2)T(5)-P,C]PF(6), where the thienyl carbon is bonded to ruthenium (P,C bonding). The P,C complexes revert back to the P,S bonding mode by reaction with acid; therefore, metal-thienyl bonding is reversibly switchable. The effect of interaction of the metal groups in the different bonding modes with the thienyl backbone is reflected by changes in alignment of the thienyl rings in the solid-state structures of the complexes, the redox potentials, and the pi --> pi transitions in solution. Methyl substituents attached to the terthiophene groups allow observation of the effect of these substituents on the conformational and electronic properties and aid in assignments of the electrochemical data. The PT(n)() ligands bound in P,S and P,C bonding modes also alter the electrochemical and spectroscopic properties of the ruthenium bis(bipyridyl) group. Both bonding modes result in quenching of the oligothiophene luminescence. Weak, short-lived Ru --> bipyridyl MLCT-based luminescence is observed for Ru(bpy)(2)PDo(2)T(5)-P,S(2), [Ru(bpy)(2)PT(3)-P,C]PF(6), [Ru(bpy)(2)PMeT(3)-P,C]PF(6), and [Ru(bpy)(2)PMe(2)T(3)-P,C]PF(6), and no emission is observed for the alternate bonding mode of each complex.
我们报道了配合物的制备，其中钌（II）双（联吡啶）基团通过二苯基膦连接基和噻吩基硫（P，S键合）与低聚噻吩配位，得到Ru(bpy)(2)PT(3)-P,S(2)（bpy = 2,2'-联吡啶，PT(3) = 3'-(二苯基膦基)-2,2':5',2''-三噻吩）、Ru(bpy)(2)PMeT(3)-P,S(2)（PMeT(3) = 3'-(二苯基膦基)-5-甲基-2,2':5',2''-三噻吩）、Ru(bpy)(2)PMe(2)T(3)-P,S(2)（PMe(2)T(3) = 5,5''-二甲基-3'-(二苯基膦基)-2,2':5',2''-三噻吩）和Ru(bpy)(2)PDo(2)T(5)-P,S(2)（PDo(2)T(5) = 3,3''''-二癸基-3''-二苯基膦基-2,2':5',2'':5'',2''':5'''',2''''-五噻吩）。这些配合物与碱反应，生成配合物[Ru(bpy)(2)PT(3)-P,C]PF(6)、[Ru(bpy)(2)PMeT(3)-P,C]PF(6)、[Ru(bpy)(2)PMe(2)T(3)-P,C]PF(6)和[Ru(bpy)(2)PDo(2)T(5)-P,C]PF(6)，其中噻吩基碳与钌键合（P，C键合）。P，C键合的配合物通过与酸反应可恢复到P，S键合模式；因此，金属-噻吩基键合是可逆切换的。不同键合模式下金属基团与噻吩主链相互作用的影响通过配合物固态结构中噻吩环的排列变化、氧化还原电位以及溶液中的π→π跃迁得以体现。连接在三噻吩基团上的甲基取代基使得可以观察到这些取代基对构象和电子性质的影响，并有助于对电化学数据进行归属。以P，S和P，C键合模式结合的PT(n)配体也会改变钌双（联吡啶）基团的电化学和光谱性质。两种键合模式都会导致低聚噻吩发光猝灭。对于Ru(bpy)(2)PDo(2)T(5)-P,S(2)、[Ru(bpy)(2)PT(3)-P,C]PF(6)、[Ru(bpy)(2)PMeT(3)-P,C]PF(6)和[Ru(bpy)(2)PMe(2)T(3)-P,C]PF(6)，观察到基于Ru→联吡啶的弱且短寿命的MLCT发光，而每种配合物的另一种键合模式则没有发射。
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